超高压磨料射流喷嘴流场分析及结构优化

摘要

To attain the optimal jet characteristics of ultrahigh pressure nozzle and improve the working efficiency of abrasive water jet cutting equipment, the calculation method of accelerating of fluid and abrasive particles in nozzle cone and cylinder section has been studied based on two-phase flow theory.The FLUENT software has also been used to simulate the internal and external jet characteristics of the nozzle.The velocity and pressure field distribution inside and outside nozzle has been studied, and the theoretical calculation and simulation results have been compared.On the basis of the study, the influences of the angle of the cone section and the length of the cylinder section on the internal and external jet characteristics of the nozzle have been studied, so that to attain the optimal structural size range of the nozzle.The results show that, for the nozzle with the inlet diameter of 8 mm and the outlet diameter of 1 mm, the recommended cylinder section length range is 30~35 mm and the cone angle range is 12°~13 °.%为得到超高压喷嘴的最佳射流特性,提高磨料射流切割设备的作业效率,基于两相流理论研究了流体和磨料颗粒在喷嘴收缩段和圆柱段内加速的理论计算方法,同时利用计算流体力学软件FLUENT对喷嘴内外射流特性进行仿真分析,研究喷嘴内、外速度和压力场分布情况,并对比理论计算与仿真结果.在此基础上,研究收缩段角度和圆柱段长度对喷嘴内、外射流特性的影响,确定喷嘴内部最优结构尺寸范围.研究结果表明:对于入口直径8 mm、出口直径1 mm的喷嘴,圆柱段长度范围宜选取30~35 mm,收缩角范围宜选取12°~13°.所得结论可为超高压磨料射流喷嘴的设计及现场应用提供参考.